There are a million things you could learn. One of the things I realized a long time ago that helped had to do with understanding the relationship between major scales and pentatonics. If you take C major for example. C D E F G A B C. C major pentatonic is C D E G A. F major pentatonic is F G A C D G major pentatonic is G A B D E. What you notice is that by combining the notes of all those pentatonic scales based of the 1, 4 and 5 of the key, you get all the notes in the major scale. What I find is that as the chords shift within a key, particularly in southern rock and country, if you change the pentatonic to fit whatever chord you're on, it sounds right. Don't do this always starting at the first note, but notice where the overlays are. If you hit the note that changed at the moment when the chords change it'll sound like you know what you're doing.
I don't often play with this kind of strict adherence to that formula, but in blues/rock/country terrain it informs what I do. You can play all kinds of stuff in a minor pentatonic blues/rock vein over a standard 3 chord set of changes and it gives it a different flavor to then blend in the kind of major pentatonic (plus all the notes in between) per chord kind of thinking...more countryish, Allman Brothersish.
Play patterns over a 3 chord vamp and only change the notes that you need to in order to stay in the pentatonic scale for that particular chord. i.e. over G play e d b a, then over F f d c a over C e d c a. It's a good way to get used to tracking the chord changes with notes that imply melodically something that has changed in the harmony.
Following up on the language piece noted above, sing phrases (even if you don't sing) and play them. Your ear probably has a much better idea of how to play lead than you do. Singing will bring out a musicality in your playing immediately. Chances are some part of you already hears what notes need to change as chords do and you just need to find them. If you start with small phrases that are singable, you'll have a musical basis to build on. And space is your friend, just like in conversation (though in some genres and solos space seems to be the enemy). Say something. Pause. Listen. Say something else. Listen.
Good luck. It's a long road to soloing well for most people.